30 TA2922 Universal Line Interface Service Manual
© Tait Electronics Limited March 2010
The radio signal source is fixed in level with AUD_TAP_OUT selected or is var ied
with the radio volume control if the RX_AUD source is selected as an option in
the TA2922 programmable options. See “RX Line Out uses RX_AUD” on
page 43.
Note that in some radio configurations, the RX_AUD level becomes fixed and is
not volume controlled, such as when some remote head or multi-head options are
in use. The frequency response of audio sourced from AUD_TAP_OUT is defined
in the programmable audio options of the radio, while audio sourced from
RX_AUD is de-emphasised. See “Programmable I/O form, Audio tab” on
page 40.
Depending on link population, the line output pair can be used for 2-wire audio
in and out and for centre tap ‘phantom’ DC keying options. Frequency response
is from 50Hz to 3kHz. See “Additional configuration links” on page 38.
J +13V8_SW
■ Signal direction: output
■ Signal level: 10.8-16VDC
■ Signal impedance: <1 ohm
Unregulated DC supply output switched by radio power on/off. 150mA
continuous or 300mA for less than one second. Protected by 300mA self-resettable
polyswitch fuse.
KAUX MIC AUD
■ Signal direction: input
■ Signal level: 15mV RMS for 60% system deviation
■ Signal impedance: 2.2k ohms
Connection for auxiliary microphone. Supports direct connection to electret type
microphone, 2.3VDC bias to operate the microphone is included on this line.
LRSSI
■ Signal direction: output
■ Signal level: 0-3VDC
■ Signal impedance: > 1k ohm
Analogue received signal strength indicator out of radio. Analogue signal is
proportional to received signal strength within the operating range of the receiver.
Refer to the radio documentation for details.
M LINE IN UNBAL
■ Signal direction: input
■ Signal level: 8mV to 1V RMS
■ Signal impedance: 50k ohms